Electrically trippable switch



Aug. 27, 1957 DEHMLOW 2,804,522

ELECTRICALLY TRIPPABLE SWITCH Filed June 29, 1955 INVENTOR.

LOUIS L. DEHMLOW A 7' TOR/VE Y United States Patent C ELECTRICALLY TRIPPABLE SWITCH Louis L. Dehmlow, Freeport, Ill., assigner to Minneapolis-Honeywell Regulator Company, Minneapolis, Minn., a corporation of Delaware Application June 29, 1953, Serial No. 364,721

3 Claims. (Cl. 200-106) This invention relates to electric switches and more particularly to a switch that may be actuated either manually or electrically.

An object of the invention is to provide a switch that may be manually operated in two directions and may be operated electrically in one of these directions.

Another object of the invention is to provide a toggle switch that is manually operable between two positions but is electrically trippable from one of these positions.

A further object is to provide a switch which will remain in either a normal or a detent position but which may be electromagnetically released from the detent position.

Other objects will be apparent from the specification and claims, and from the drawing, in which:

Figure l is an elevation, with cover removed and partly in section, of a switch incorporating the invention,

Figure 2 -is a fragmentary section as seen from the right in Figure l but with the parts in another operative position,

Figure 3 is a fragmentary elevation similar to Figure l, but with parts shown in a transitory condition, and

Figure 4 is a schematic showing of the electromagnet energizing circuit.

The device utilizes a plunger operated snap switch movable between its two operative positions by a manually operable toggle lever, a spring detent being employed to hold the toggle lever in the position in which the plunger of the snap switch is depressed. The spring detent is movable by an electromagnet to a position in which the toggle lever is released, thereby permittingthe snap switch to return to the position in which the plunger is in its ex-` tended position.

Referring to the drawing, a frame forms four sides of a box, with the remaining sides formed by a terminal block 11 of insulating material and a cover, not shown, which may be secured in place by screws entering three posts 12, 13, and 14 affixed to the inner surface of the frame. The surface of the frame lying at the right in Figures l and 3 may be secured to a panel, and for this purpose nuts 17 and 18 are permanently attached to this portion of the frame.

A precision snap switch 20 of the self-returning type is secured by screws 21 and 22 to the rear surface of the frame 10. This switch is of the type disclosed in Kaminky Patent 2,486,033 to which reference may be had for details of construction and operation. The switch 20 is operated by a plunger 25 which in the raised position shown in Figure 1 causes switch terminals 26 and 27 to be electrically connected, and in the depressed position of Figure 3 interconnects terminals 26 and 28. Switch terminals 26, 27, and 28 may be connected by suitable lead wires to terminals 31, 32, and 33 on the terminal block 11.

A spring strip 30 is carried at its left end by the frame 10 and has a portion overlying the plunger 25. A toggle lever 35 is pivoted in the frame 10 on a pin 36, and

2,804,522 Patented Aug. 27, 1957 ICC has an outer end 37 in the form of a manually positionable bat handle and an inner end 38 adapted to engage the spring strip 30 which, on movement to the position shown in Figure 3, depresses the plunger 25 to actuate the switch 20. A bracket 40 secured to frame 10 locates the pivot pin 36 with respect to the frame and coopera-tes with the inner end of the toggle lever to confine movement thereof to limits shown by Figures 1 and 3. The spring strip 30 is preformed to bias the toggle lever, when otherwise free, to the position shown in Figure l. A rubber boot 41 seals the opening between toggle lever 35 and the frame 10.

A spring detent strip 42 is pivoted in the frame 10 on the cover mounting post 12 which is provided with a shoulder confining the strip 42 to oscillatory movement about an axis that is parallel to the pivotal axis of the toggle lever 35. As best seen in Figure 2, the lower end of the detent strip 42 is formed to provide a hill over which a pin 43 extending laterally from the inner end of the toggle lever must pass in moving the toggle lever from the position shown in Figure 1 to the position shown in Figure 2. The detent strip 42 exerts an outward force on the pin 43 of sufcient magnitude and engages the pin at such an angle that the component of force holding the toggle lever in the position of Figure 2 exceeds the biasing efect of the spring strip 30 and the plunger 25 and thereby maintains the switch in the position shown in Figure 2. The toggle lever 35 may be returned manually to the position shown in Figure l by forcing the pin 43 past the hill on the detent strip 42. When the toggle lever is in the position shown in Figure 1 the pin 43 is out of engagement with the detent strip 42 as shown in the dotted line position indicated in Figure 2. It is not essential that pin 43 be separated from the strip 42 as illustrated. The strip must, however, be freely movable beneath the pin 43 as will appear below. A ball 44 is interposed between the detent strip 42 and the adjacent surface of the frame 10 to provide a bearing surface therebetween that permits reasonably free lateral movement of the detent strip in removing the strip from beneath the pin 43 as will appear hereinafter.

In what may be termed normal operation, the device acts as a toggle switch of the type that will remain in either of two operative positions.

An electromagnet 46 has a magnetic frame 47 secured to frame 10 and includes a winding 48 and an armature 49 which is pivoted in the frame 47 on a pin 50. The armature 49 carries an arm 51 which in the energized position shown in Figure 3, engages a switch blade 52 to separate a pair of contacts 53 and 54, which are connected across a portion of the winding 48. The winding 48 is connected by wires which have been omitted from the drawing to terminals 55 and 56 on the terminal block 11. When the armature 49 is moved to energized position the Winding portion 48a of relatively high resistance is placed in series with winding portion 48b to reduce current consumption as shown in Figure 4.

A tension spring 58 interconnects the arm 51 and post 13 to move the armature in a counterclockwise direction when the electromagnet is deenergized. The armature is provided with a bracket 49a having a portion spaced from the armature but lying parallel thereto and embracing an angular portion 42a of the detent strip 42. The strip 42 is also provided with a lateral extension 42b which abuts the frame 10 to determine the position of the detent strip and hence the position of the armature when the electromagnet is deenergized.

Figure 3 shows a transitory position of the parts which will occur immediately after energization of the electromagnet. The bracket 49a on the armature 49 has moved the detent strip 42 in a clockwise direction so that it no longer engages the pin 43 on the inner end of the toggle lever 35. The biasing effect of the spring strip 30 will, of course, immediately move the toggle lever 35 in a clockwise direction to the position shown in Figure l. As long yas the electromagnet remains energized the Vdetent strip 42 will be out of position for engaging the pin 43 on the toggle lever and the switch will not remain in the position in' which the plunger 25 is depressed. However, when the toggle lever is in the position shown in Figure 1 and the electromagnet is deenergized, the spring 58 will return the armature 49 and hence the dctent strip 42 to a position in the path of movement of the pin 43, permitting normal operation of the switch.

Various changes could be made'in construction without departing from the spirit of the invention` Forexample, the spring strip 30 intermediate the toggle lever and the plunger might be omitted and the parts disposed so that the toggle directly engages the switch actuating means. The invention is to be limited only by the scope of the appended claims.

|I claim as my invention:

1. An electric switching device comprising, a frame, an actuating lever pivotally mounted in said frame and movable between iirst and second positions, means biasing said lever to its first position, switching means actuated by said lever on movement between its two positions, impositive latch means movable between an effective and an ineffective position and having a surface portion adapted when said latch means is in its effective position to engage said lever in its second position and prevent movement thereof by said biasing means, said surface portion being deectable by said lever in a direction parallel to the pivotal axis of said lever and said latch means being movable in a path toward and away from the pivotal axis of said lever, means biasing said latch means to its effective position, and an electromagnetically actuated device articulated with said latch means and adapted to move said latch means to its ineffective position.

v2. An electric switching device comprising, a frame, an actuating lever pivotally mounted in said frame and movable between first and second positions, means biasing said lever to its first position, switching means actuated by said-lever on movement between its two positions, impositive latch means movable between an effective and an ineffective position and having a surface portion adapted when said latch means is in its effective position to engage said lever in its second position and prevent movement thereof by said biasing means, said sur` face portion being de-ectable by said lever in a direction parallel to the pivotal axis of said lever and said latch means being movable in a path toward and away from the pivotal axis of said lever, and means for moving said latch means between its .effective and ineffective positions.

3. An electric switching device comprising, a frame, an actuating lever pivotally mounted in said frame and movable between yfirst and second positions, means biasing said lever to its tfirst position, switching means actuated by said lever on movement between its two positions, a member pivoted in said frame on an axis parallel to the pivotal axis of said lever, said member having a spring biased surface adapted to engage said lever and in one position of said member to be deflected by said lever Vin a direction parallel to the pivotal axis of said member on movement of said lever between its two positions and to maintain said lever in its second position against the effect of said biasing means, said surface being formed and so disposed with respect to the pivotal axis of said member as to permit pivotal movement of said member when engaging said lever in its second position without increasing the bias of said surface, and electromagnetic means acting on said member for pivotally moving said member to disengage said spring biased vsurface from said lever,

'ReferencesCited in the file of this patent UNITED STATES PATENTS 735,170 Stewart Aug. 4, 1903 1,207,016 Fryer Dec. 5,1916 1,902,700 .Hadano Mar. 2l, 1933 2,231,686 Shaw Feb. 11, 1941 2,422,471 Cyr June 17, 1947 2,486,033 Kaminky Oct. 25, 1949 2,656,426 -Dibelka Oct. 20, 1953 

